In conventional magnetic resonance imaging (MRI) systems, three types of magnetic fields are conventionally utilized to obtain an image of an object. A first or primary magnetic field, termed the B0 field is static in time and substantially homogenous inside an imaging volume. The B0 field typically determines a resonance frequency of the atoms of the object being imaged, depending on the gyromagnetic ratio of the atoms.
Further, to obtain an image of the object, the Mill system typically generates a spatially modulated resonance frequency of the object, which is provided by the second type of magnetic fields termed gradient fields. The aim of the modulation can be in various forms such as slice selection, phase encoding and frequency encoding. However, the gradient fields are typically configured to discriminate different spatial locations by applying additional magnetic fields, which can have certain spatial dependencies. In conventional MRI scanners, there are three gradient coils called x-gradient, y-gradient and z-gradient that are used to encode three spatial dimensions. During an imaging sequence, spatial encoding of the object can change as a function of time for imaging purposes. Accordingly, an MRI system typically drives gradient coils dynamically as a function of time and wideband current waveforms are necessary.
Conventionally, an MRI system drives each of the three gradient coils with a relatively high power amplifier. Typically, each of the three gradient coils can generate a linearly changing magnetic field in its corresponding dimension (x-, y, or z-axes), which are termed linear gradients.
The third type of magnetic field generated by the MRI system is termed a radio frequency (RF) field. The MRI system utilizes the RF field to excite spins within the object being imaged.